Aluminum-chloride process



y 21, 1929- H. LEA ET AL- 1,713,968

ALUMINUM CHLORIDE PROCES S Filed May 51, 1922 [72 2/4972 to rs [[97273]I Z ea Chflord Mllumpkrqy.

Patented May Zl, 1929.

UNITED STATES PATENT OFFICE. I

HENRY I. LEA, OF SANTA MONICA, AND CLIFFORD W. HUMPHREY, GLENDALE,

CALIFORNIA.

ALIJ'MINUM-GI-ILO RIDE A PROCESS.

Application filed May 31,

This invention relates generally to processes for the production ofaluminum chloride and more particularly'to processes for thechlorination of aluminum oxide. It will be understood that aluminumoxide for use in this process may be either in the pure state or carriedwith foreign material such as ore, although hereinafter such aluminacarrying substance will be referred to as aluminum oxide.

The present process may, though not neces' sarily, conveniently be usedin .cOn unct on with our process for making aluminum oxide, whichprocess with various related procedures are fully described in ourPatent No. 1,646,733, titled Aluminum chloride process issued October25, 1927. Briefly stated, this preferred process embodies decompositionby heat of aluminum sulphate, either pure or carried in foreignmaterial, to;- form aluminum oxide and certain gaseous products. Thelatter, through suitable processing, are

used in the production of chlorine which may.

then be used for the chlorination of the alu mina formed earlier in theprocess. The sulphate may be decomposed in a battery or retorts so as toeffect continuous production of aluminum oxide and of aluminum chloridefrom that oxide, for instance by the hereinafter described chlorination,process, in that one or more of the retorts may be cut from the batteryfor recharging or for carrying out a chlorination process and thenrecharging without interrupting the operation of the battery as a unit.

Althoughit will be understoodthat the present invention and the presentprocess'are not limited to being carried out in conjunction with anyparticular method or process for making aluminum oxide, it is preferablethat the present method start with a pure aluminum oxide, and theforegoing indicated methods are convenient because they not only producepure aluminum oxide in good form for chlorination, but also becausethey. at the same time, produce pure chlorine suitable for use in thechlorination operation.

In the accompanying figure we have shown conventionally a retort m whichour process may conveniently be carried out, and al-- though the processis not restricted to the use of this particular ype of retort or to anysingle retort, the illustrated retort will be described for the purposeof clearly setting 1922. Serial a. 564,762.

for the process rather than the particular apparatus used. Adiagrammatic sectional elevation of the retort is indicated in thefigure. A retort drum 10 is supported by brickwork 11 which also definesacombustion chamber 12 extending around and underneath the drum. Fuelmay be introduced into the chamber at 13 and burned therein for thepur-' pose of heating the retort drum 10. This drum, which maybe of anydesired shape, is shown to contain a charge of aluminum oxide and to beclosed by means of head 10. 'A gas inlet line to drum 10 is shown at 17.Vapor line 14 interconnects the drum with condensing chamber 15, whichis provided with thoroughly with carbon or carbonaceous materials. Thismay be done whether these materials be in solid, liquid or gaseous form.

In case carbon or hydrocarbon in solid formis used, it may be mixed withthe charge before the latter is placed in the retort drum, and themixture may bebriquetted if found desirable to prevent its being carriedover mechanically into the condensing chamber during its subsequentheating. If the charge has not been impregnated with carbonaceousmaterial before being admittedto the drum, we have found it to bethoroughly satisfactory to impregnate the charge with hydrocarbons inliquid or gaseous phase sprayed thereon through spray 18. During thisprocedure the retort drum and charge are kept hot enough to decomposethe hydrocarbons and thereby deposit carbon. At the completion of theimpregnating procedure, the ex-.

some of the condensed hydrocarbons and may be somewhat sticky and cokeyand semiliquid, less liable to deterioration but not ob jectionable foruse in oil distilling processes. When the chlorine is allowed to reactwith the aluminum oxide the retort is kept at a temperature of about redheat to facilitate the formation ofaluminum chloride accord ing to thefollowing reaction:

Thus carbon monoxide and anhydrous aluminum chloride are produced invapor form. The gaseous mixture passes into the condensing chamber 15wherein the aluminum chloride sublimes and the carbon monoxide passesout through a line 16. The carbon monoxide may be used as fuel for theretort.

It may be desirable to control the temperature at which the aluminumchloride sublimes, so as to predetermine its final physical form. In theaforementioned patent we have shown and described a specific type ofcondensing chamber in which means are provided for controlling the walltemperatures of the chamber to obtain the form of sublimate desired.

Whereas we have not endeavored to illustrate or describe all thepermissible variations in our process from the relatively limitedapplication in the specific type of apparatus shown, it will beunderstood that the process may be varied to accommodate other apparatusand to conform with other procedures and still be within the scope ofthe specific subject matters of several divisional applications asfollows:

Application B, Serial No. 646,555, filed June 20,1923.

Application C, Serial No. 646,556, filed June 20, 1923.

Application D, Serial No. 646,557, filed June 20,1923.

' Application E, Serial No. 646,558, filed June 20,1923.

Application F, Serial No. 646,559, filed June 20,1923.

Having described a preferred form of our invention, we claim:

1. A process of the character described herein, that includesimpregnating aluminum oxide with hydrocarbon to supply car bon in excessofthe requirements of chlorination, and chlorinatingth impregnated oxideto form anhydrous aluminum chloride impregnated with hydrocarbons.

2. A process of the character herein described, that includesimpregnating with hydrocarbons hot aluminum oxide in a retort by passinghot hydrocarbon vapors into the retort in suflicient quantity'toimpregnate the oxide with hydrocarbons carrying an excess of carbon overthat required for' chlorination action.

3. A process of the character described, that includes impregnating withhydrocar bons hot aluminum oxide in a retort by pass ing hot hydrocarbonvapors into the retort; clearing theretort of excess hydrocarbon vaporsbypassing a neutral gas through the retort, and then chlorinating theimpregnated oxide in the retort.

4, A process of the character herein described, that includesimpregnating an alumina bearing substance with hydrocarbons andchlorinating the impregnated substance.

In witness that we claim the foregoing we have hereunto subscribed ournames this 24th day of May, 1922.

HENRY I. LEA. CLIFFORD W. HUMPHREY.

